Homemade Pasta · Research

AI Overviews and your organic volume

Google's AI Overviews reduce organic clicks by roughly 40% on the queries where they appear. Optimizing for citation recovers part of that. A ceiling of 38% does not come back at all. This is what the evidence supports, what it is worth, and what to put on the board first.

PublishedSeptember 2026
ReadAbout 12 minutes

Why this exists

The decline shows up everywhere. The size of it does not.

Homemade Pasta runs paid media for clients in categories with little in common. Organic search volume is down across the client base. Their organic teams keep asking the same question the rest of the industry is asking, and the answers on offer are a single vendor study or a single account’s dashboard.

Neither one plans a year. Published estimates of the AI Overview effect range from 15% to 58%, a band too wide to budget from. One account cannot narrow it either, because a single set of dashboards cannot separate an AI Overview effect from a ranking change, a seasonal shift or a tracking break.

So we read the evidence ourselves. This page consolidates what holds up into one calibrated number, then turns that number into a plan. What to measure first, what to fund, what to stop funding, and what to take out of the forecast permanently.

Executive summary

The pot is smaller. The share is still winnable.

Organic clicks lost−39.8%Where an AI Overview appears
Value of a citation+29%Versus present but uncited
Structural ceiling−38%Cited, versus no AI Overview
Paid CTR retained80%Against 62% for organic

Three findings determine how much to invest, what to forecast, and how to split search budget.

  1. The loss is large and it is measured. A randomized field experiment found that when an AI Overview appears, outbound organic clicks fall 39.8% and zero-click searches rise 34.5%. Sponsored clicks and total search frequency are unaffected.
  2. Citation optimization recovers a fraction, not the whole. Pages cited inside an AI Overview earn 29% more organic clicks per impression than pages present on the same results page but uncited. They still earn 38% fewer clicks than the same queries returned before an AI Overview appeared on them. That 38% is structural and no amount of optimization reaches it.
  3. Paid search is the more resilient half of the results page. Comparing a clean results page to one where the brand is cited, organic click-through falls 38% while paid falls 20%. Paid click-through on AI Overview queries has risen over the measurement period while organic has fallen.

The practical consequence is a change in forecast, not only a change in tactics. An organic plan built on recovering pre-AI-Overview volume will miss. An organic plan built on capturing the largest available share of a smaller pool, with search budget rebalanced toward the channel that holds up better, will not.

Recommendations

Mise en place, in order of return

ActionWhy it comes firstQuantified impact
1. Measure exposure before anything else The share of organic impressions sitting on AI Overview-present queries determines the size of every other number here. Most organizations do not have it. Below 15% exposure, this is a minor program. Above 40% it is the highest-value organic work available.
2. Audit crawler access and snippet eligibility The only work every major platform documents as necessary. A nosnippet directive or a bot rule at the CDN removes AI Overview eligibility outright, and neither is visible in a standard SEO audit. Removes a binary risk of total exclusion. Costs days, not quarters.
3. Fund citation work in proportion to exposure Ranking still governs eligibility. It no longer governs the outcome, so citation is a separate objective from position. Doubling a citation rate from 25% to 50% returns 7% to 23% more organic clicks on the affected query set.
4. Hold or increase paid coverage on affected clusters Informational and comparison queries carry the heaviest AI Overview exposure. Paid performance on those queries has been stable while organic has compressed. Paid retains 80% of its clean-page click-through where the brand is cited. Organic retains 62%.
5. Reset the organic forecast The structural shortfall is not addressable by content, markup or technical work. Carrying it as a performance gap misallocates effort for several quarters. Perfect citation performance returns 62% of pre-AI-Overview clicks on affected queries. The remaining 38% should be planned as permanent.

Part One

What comes off the plate

The size of the loss, where it concentrates, and what happens to paid search on the same pass.

1.1 The loss

One clean measurement beats four estimates

Estimates of the organic click decline when an AI Overview is present range from 15% to 58%. Four are observational. One randomized users, and it lands in the middle of the range at 39.8%. That figure should anchor any forecast.

Amsive Seer Interactive Agarwal & Sen Authoritas Ahrefs, position 1 −15.5% −26% −47.5% −58% −39.8% RANDOMIZED 0% −15% −30% −45% −60%
Change in organic clicks when an AI Overview is present. Four of these measure click-through rate. The randomized estimate measures outbound click volume, which is one reason it is marked separately rather than averaged in. All five measured different populations.2, 3, 5, 6, 7

The spread reflects measurement populations rather than disagreement about direction. The narrowest estimate was taken only on keywords where the site already held a ranking. The widest spans two years, is position-one specific, and is desktop only.

The blind testJanuary to February 2026

Participants were randomly assigned through a browser extension to standard Google Search, to a version with AI Overviews suppressed, or to AI Mode. Approximately 1,065 US desktop Chrome users and 68,089 searches.

Conditional on an AI Overview appearing, outbound organic clicks fall 39.8% and zero-click searches rise 34.5%. Sponsored clicks do not move. Total search frequency does not move.

A secondary result carries equal weight for planning. Google's stated explanation is that AI Overviews suppress low-value clicks and that surviving clicks are higher quality. Measured against the control group, downstream engagement per click did not improve.5

A separate behavioral panel establishes the corollary. Users click a link inside an AI Overview in approximately 1% of visits to pages carrying one, against 8% clicking a traditional organic result on those pages and 15% on pages with no AI summary.9 Citation is not a distribution channel. It is a position advantage on the organic clicks that still occur.

Where exposure concentrates

Query shape governs exposure more than industry does. Across 55,393 queries, question-form queries triggered an AI Overview 64.7% of the time against 9.5% for non-question queries, a 6.8-fold difference. “How” queries reached 84.3%. Single-word queries reached 9.9%. A separate dataset places comparison queries, the “X versus Y” format, at 95.4%.1, 2

“How” queries84.3%
Question-form queries64.7%
Six words or more, not a question38.7%
Single-word queries9.9%
Not a question9.5%

These groups overlap rather than partition. The sample is of trending queries, which skew question-shaped, so the direction is firm and the absolute rates are probably high. Preprint, under review.1

By intent, informational queries carry most of the exposure at 36% prevalence, against 8% commercial and 5% transactional. Transactional queries are now affected as well: organic click-through on AI Overview-present, uncited transactional queries fell from 4.17% to 2.15% across 2025.2

Brand strength is protective. Branded keywords with an AI Overview present gained 18.68% click-through in one study while non-branded lost 19.98%, and only 4.79% of branded keywords triggered an AI Overview at all.3 Across thousands of publisher sites, search referral traffic over two years fell 60% for small publishers, 47% for mid-sized and 22% for large.4

How AI Overviews select sources

Google documents the architecture, and it determines which levers exist. AI Overviews are produced by retrieval-augmented generation, described by Google as a technique “used to improve the quality, accuracy, and freshness of AI responses by relying on our core Search ranking systems to retrieve relevant, up-to-date web pages from our Search index.” The same systems that rank organic results supply the candidate set, which is why ranking remains the strongest available lever.

Google also generates fan-out queries, a set of concurrent related searches run alongside the query the user typed. A page can therefore be cited without ranking for the visible query.

Independent measurement confirms the second mechanism is material. Across 55,393 queries, 29.8% of AI Overview-cited domains did not appear anywhere in the first-page organic results displayed beside them. Source selection is partly a separate retrieval process rather than a re-ranking of page one.1

Two further findings from the same study bear on content strategy. AI Overviews cite more credible sources than the organic results beside them, scoring 0.732 against 0.645 on a continuous credibility measure with a 95% confidence interval of 0.085 to 0.089 on the gap. And they under-cite user-generated content, which accounts for 14.2% of AI Overview references against 41.4% of first-page results.

Part Two

What goes back on

The value of a citation, the ceiling above it, and a model that portions both against a specific set of impressions.

2.1 The citation premium

A citation is worth 29%. The ceiling is 38%.

Pages cited inside an AI Overview earn more organic clicks than pages that appear on the same results page without a citation. That premium is real, it is bounded, and both halves matter to a forecast.

The published figure for the premium is +120%. The figure to plan against is +29%. The gap between the two sits in the publishing study's own methodology appendix, quoted in full below.

“The Informational AIO – Brand Not Cited aggregate CTR (0.94%) is materially influenced by one account representing 47% of that segment's impressions at 0.20% CTR. Excluding that account, the aggregate is approximately 1.61%.”Seer Interactive, 2026 update, methodology appendix

With the uncited baseline corrected from 0.94% to 1.61%, the premium falls from +120% to +29%. Incremental clicks fall from 11,298 to 4,643 per million impressions. An earlier study on a different cohort placed the same premium at +35%, which supports the lower figure.

Organic clicks per million impressions Informational queries, AI Overview present
Uncited baseline
12,757 structural No AI Overview the counterfactual Cited best achievable Present, not cited where most pages sit 33,500 20,743 16,100 +4,643 won by citation
Full-year 2025 averages, informational intent. Underlying click-through rates: 3.35%, 2.07%, and 1.61% adjusted or 0.94% as published. 53 brands, 5.47 million queries, 2.43 billion organic impressions.2

The ceiling

The structural gap does not move when the baseline is corrected, because the excluded account sits only in the uncited segment. On click-through, 2.07 divided by 3.35 is 0.618. On clicks per million, 20,743 divided by 33,500 is 0.619. A page that wins every citation it competes for still earns 38% fewer organic clicks on those queries than they returned before an AI Overview appeared on them.

That figure is the single most important input to an organic forecast, and it is the one most commonly omitted. Optimization improves position within a diminished pool. It does not restore the pool.

Qualifications on this figure

Citation status in the source study is a static label taken from the most recent results-page snapshot and applied backwards across fourteen months. Given that AI Overview citations turn over roughly every two days, that label is a proxy rather than a measurement. The publisher states it cannot claim causation.

The premium does not generalize across intent. On transactional queries in the same dataset, uncited pages outperformed cited pages for most of 2025. The direction reverses, and the informational figure should not be applied to a transactional query set.

The same study reports a reversal in early 2026: organic click-through on AI Overview-present queries climbed from a floor of 1.3% in December 2025 to 2.4% in February 2026. Two months is not a trend, and the publisher's own model underestimated the recovery. The 2025 averages remain the best available central estimate; the 2026 movement is unresolved.

2.2 Sizing

Portion it against your own impressions

The figures above are expressed per million impressions. The number that determines their significance is the share of a given site's organic impressions that sit on AI Overview-present queries.

Value of a citation program

Informational queries with an AI Overview present. All outputs recalculate, including the counterfactual click volume at the no-AI-Overview rate.

Exposure
50M
Search Console, total impressions, last 12 months
30%
Cross-reference impressions against your rank tracker's AI Overview flag
25%
Share of those queries where you are cited today
50%
Constrained to the current rate or above. Doubling is an ambitious target.
Switches the uncited CTR between 1.61% and 0.94%
Additional organic clicks per year +17,250 +6.7% on the affected query set
Impressions on AI Overview queries15,000,000
Organic clicks today258,750
Organic clicks at target276,000
At the no-AI-Overview click rate502,500
Gap to the no-AI-Overview rate243,750
Share of that loss recovered7.1%
Worth funding

A defined program with a named owner. The gain sits inside what a quarter of focused work can move, though it will not appear cleanly in Search Console reporting.

Uses 2.07% cited and 3.35% no-AI-Overview CTR throughout, with the uncited rate set by the toggle. The 3.35% is a contemporaneous rate on queries that do not trigger an AI Overview, not a measured pre-2024 baseline, and those are different query populations. Informational intent only, from a single 53-brand dataset whose publisher states it cannot claim causation. Treat the output as an order of magnitude, not a forecast.

How to read the output

  • Perfect execution returns 62% of pre-AI-Overview clicks on the affected queries. Citation on every query yields 20,743 clicks per million against a 33,500 counterfactual. No configuration of the inputs recovers the remainder.
  • Doubling a citation rate is an ambitious target and returns a single-digit to low-double-digit percentage of the loss. That is a worthwhile return. It is not a restoration.
  • Exposure determines whether this is a program or a task. Below roughly 15%, the absolute gain does not justify dedicated staffing. Above 40%, it is the largest single opportunity in an organic plan.

Part Three

How to put it there

The practices the evidence supports, the practices it does not, and the one that burns the dish.

3.1 Practices

Five worth the prep, six to drop

Ordered by the strength of the evidence behind each.

Show
Rank in the top 10

90% of AI Overviews cite at least one top-10 organic result, and a page ranking first is cited about 43% of the time, falling to 7% at position 20. Only 38% of individual citations are top-10 URLs, down from 76% a year earlier. Ranking governs eligibility rather than outcome.8

Keep pages snippet-eligible

Google requires a page to be indexed and eligible to display with a snippet in order to appear as a supporting link. A nosnippet or max-snippet:0 directive removes AI Overview eligibility outright. This is the most common self-inflicted exclusion and it costs nothing to verify.

Permit crawlers at the CDN, not only in robots.txt

Google's published checklist specifies that crawling be allowed “in robots.txt, and by any CDN or hosting infrastructure”. Firewall and bot-management rules do not appear in a robots.txt audit and are the dominant real-world cause of exclusion. Google-Extended governs Gemini training and grounding only and has no bearing on AI Overviews.

Publish non-commodity content

Google's guidance draws the boundary at content that “could easily be produced by a generative AI model”. With a median of eight citations per AI Overview and a measured preference for higher-credibility sources, undifferentiated content competes for a materially narrower opening than it did against ten ranked links.

Front-load substance on the page

Analysis of Google's grounding layer found a median budget of 1,929 words per query and 377 words selected per source, with coverage falling from 61% on pages under 1,000 words to 13% on pages over 3,000. The measurement covers the Gemini grounding API rather than AI Overviews directly and dates from December 2024, so it is indicative rather than definitive.

Adding schema markup to win citations

1,885 pages that added JSON-LD, matched against 4,000 control URLs on other domains in a difference-in-differences design with an event study confirming no pre-treatment drift, produced a 4.6% decline in AI Overview citations, statistically significant. Cited pages are three times more likely to carry schema, and that correlation did not survive causal testing. Schema remains justified on rich results, which is a documented and measurable benefit.

Publishing an llms.txt file

Google states that Google Search ignores the file. Across 137,210 domains, 97% of published llms.txt files received zero requests over a month, and the largest single category of requester was SEO audit tooling.

Chunking content into smaller pieces

Google states there is “no requirement to break your content into tiny pieces for AI to better understand it” and that “there's no ideal page length”. Microsoft's guidance for Copilot takes the opposite position, making this a per-platform decision rather than a general practice.

Pursuing Reddit and forum presence for AI Overviews

AI Overviews under-cite user-generated content relative to the organic results beside them, at 14.2% of references against 41.4% of first-page results. Source-type share is also unstable: Reddit appeared in roughly 60% of ChatGPT responses before mid-September 2025 and roughly 10% after, with no content changes anywhere.

FAQPage schema

Google deprecated the FAQ rich result in May 2026. The feature that markup powered no longer appears in search results.

Core Web Vitals as a visibility lever

Across 107,352 pages appearing in AI Overviews and AI Mode, Largest Contentful Paint correlated with AI visibility at −0.12 to −0.18 and Cumulative Layout Shift at −0.05 to −0.09. Performance is a threshold to clear rather than a lever to pull.

Building content against fan-out query variations

Google's guidance states that creating separate content for query variations, “for example, by focusing on other queries that people have asked, or fan-out queries”, primarily to manipulate rankings or generative AI responses, “violates Google's scaled content abuse spam policy”. Google extended its spam policies in May 2026 to cover manipulation of generative AI responses explicitly.

Appendix

Back of house

Supporting detail behind the findings above. Open what is relevant.

A.1 Measurement

AI Overview clicks are not reported, and there is no workaround

This constrains every claim an organization can make about its own AI Overview performance, and every claim made on its behalf by a vendor. Google's Search Console generative AI report provides impressions only, with no clicks, no click-through rate, no position and no query dimension. AI Overview clicks are folded into the standard performance report with no means of segmenting them. Both limitations are documented by Google rather than inferred.

The practical consequence is that a citation program must be measured on citation rate, which is observable through third-party rank tracking, rather than on attributable clicks, which are not.

What each measurement source provides
SourceProvidesDoes not
Search Console, generative AI reportImpressions from AI Overviews and AI Mode by page, country, device and date. Worldwide since 31 August 2026.No clicks, click-through rate, position or query dimension. 1,000-row limit, manual export, not exposed in the documented API. Data begins 18 May 2026. A subset of Web-type impressions, so the two are never summed.
Search Console, standard reportAI Overview clicks are included in the totals.Undifferentiated. An AI Overview occupies a single position with all links assigned that position, which distorts average position.
Bing Webmaster Tools, AI PerformanceThe only first-party query-side citation data available: grounding query intents, topic clusters, citation share.No API. Microsoft states citation share does not represent traffic share or assign quality scores.
GA4, AI Assistant channelAssistant referrals, from 13 May 2026.Not retroactive. Perplexity is excluded. Referrer-less traffic remains in Direct.

Google formerly appended a text fragment to some AI Overview citation clicks, and a technique for capturing it in a tag manager circulated widely. Two independent practitioners who published that technique have marked it discontinued, reporting that Google moved to inline links without text fragments around May 2026. The frequently quoted finding that 22.4% of AI Overview traffic misattributes to Direct derives from this method and is now historical.

Tracking assistant referrals in GA4

A custom channel group, configured alongside the native channel rather than in place of it. Condition on Session source matches regex, ordered above Referral, since GA4 evaluates channels in sequence. Add a second condition group where Source matches the same pattern and Medium is (not set), to capture sessions where a source-only parameter prevents referrer fallback. GA4 regex matching is case-sensitive.

^(?:chatgpt\.com|chat\.openai\.com|claude\.ai|perplexity\.ai|gemini\.google\.com|copilot\.microsoft\.com|meta\.ai|grok\.com|deepseek\.com|you\.com)$

This captures the assistants. It cannot capture AI Overviews or AI Mode, which arrive as google / organic and are indistinguishable from a ranked-result click.

Two reporting errors to avoid

A falling click-through rate is frequently not lost clicks. In one 53-brand dataset, click-through fell 52% in a single month while absolute clicks rose from 398,798 to 400,271. Impressions doubled. The following month is when clicks actually declined, by approximately 25%.

Impressions Clicks
0 50 100 150 200 250 209.5 250.0 100.4 75.7 September 2025 October November Indexed: September 2025 = 100 for each series
Brands cited inside AI Overviews on informational queries. Actuals: impressions 15,797,234 to 33,100,739 to 39,500,144; clicks 398,798 to 400,271 to 301,783.2

Click-through rate should never be reported without absolute clicks alongside it. Where AI surfaces inflate impressions, the ratio alone is uninformative.

Per-query citation tracking has a noise floor above the effect size. Across 43,000 keywords each with at least sixteen recorded AI Overviews, consecutive AI Overviews for the same query shared only 54.5% of their cited URLs. An AI Overview has a 70% chance of changing between observations and persists about 2.15 days before substantive rewriting. Semantic similarity between consecutive responses is 0.95, so meaning is stable while citations churn.12

A citation KPI therefore requires a rolling aggregate across a large, fixed query set, a window of four weeks or more, a stated band rather than a point estimate, and a query set held constant between periods.

Testing designs, including one that does not work

Google's Search Console control that excludes a property from AI Overviews appears to offer a deliberate holdout. Three problems make it unsuitable on a revenue-bearing property. Recovery time is undocumented: Google publishes only that exclusion applies within one to two days and states nothing about re-inclusion. Granularity is property-level, producing one treated unit and one control unit that differ systematically. And the outcome is confounded, because Search Console reports no AI-feature clicks, so the measurable quantity is total Web clicks. Google states that sites opting out “will not receive any traffic or impressions from these features”.

A page-group holdout using nosnippet provides per-URL granularity but also removes the ordinary organic snippet, so the measured effect combines both. Practitioners have documented content reappearing days later despite the directive remaining in place.

The defensible design is a pre-and-post on aggregate citation rate across a fixed query set, with a matched control set of queries that do not trigger AI Overviews. It does not isolate causality but it separates site-level movement from platform-level movement. A matched-market test on content built for high-prevalence clusters, measuring branded search volume and direct sessions rather than organic clicks, is the only design that would establish whether citation carries value beyond the click. No such test has been published.

A.2 Adjacent channels

Assistant referrals are 0.2% to 0.3% of site traffic

ChatGPT and the other assistants generate high-intent traffic at a volume roughly two orders of magnitude below the AI Overview question. Tripling assistant referrals from 0.3% adds about six tenths of a percentage point to total sessions. Where 30% of organic impressions sit on AI Overview-present queries, AI Overviews are already moving a double-digit share of organic volume. That comparison determines sequencing.

Sizing, value, and where assistant work differs from AI Overview work
Share of site traffic0.2–0.3%Two largest independent panels
Global AI referrals771MMonthly visits, +117% YoY
Conversion vs non-AI+60%US retail, July 2026
Growth, US retail+62%Year on year, July 2026

Growth is normalizing. Adobe measured the same US retail series at +4,700% year on year in July 2025, against a near-zero base, and at +62% in July 2026. Those are separate reports against incomparable bases, which is why four-figure growth rates should not be quoted as current.10

The traffic performs well on arrival. In US retail, AI-referred visitors convert at a 60% higher rate than non-AI traffic and generate 53% more revenue per visit, reversing a substantial deficit measured in late 2024. Two qualifications apply: the traffic is heavily self-selected, and a study of roughly 82,000 websites in mid-2025 found the opposite on engagement, most plausibly explained by the twelve-month gap and by sector mix.

Across 127,198 citations from approximately 16,400 AI answers spanning five engines, only 2.7% of cited domains were cited by all five, and 69.6% were cited by exactly one.11 No single set of changes produces visibility across all of them.

Where the work differs by surface
DimensionGoogle AI OverviewsAssistants
JavaScriptGooglebot renders it.Measured crawler behavior found OAI-SearchBot, GPTBot, ClaudeBot and PerplexityBot do not execute JavaScript. Measured December 2024, with no published replication since.
FreshnessCited pages average 1,432 days old, 16 days older than the organic results beside them. Not a lever.ChatGPT cited pages average 958 days, roughly 458 days newer than organic. A lever.
Sources per answerMedian 8 references.ChatGPT averages about 15. Gemini averages 3.
Freshness submissionGoogle is not listed among IndexNow participants.IndexNow reaches Bing and therefore Copilot. Not OpenAI, Anthropic or Perplexity.

Sequencing. The access and snippet audit first, since it is inexpensive and covers both surfaces. The AI Overview citation program second, sized against measured exposure. Assistant-specific work third, and revisited if assistant referral share on a given site passes roughly 2%.

A.3 Sources

Every ingredient, with its source

Numbered references appear inline throughout. Each entry states the publication date, the sample, and whether the publisher sells a product in the category the finding supports.

Source register
1Xu, Iqbal and Montgomery, Measuring Google AI Overviews, arXiv:2605.14021, submitted 13 May 2026, preprint under review. 55,393 trending queries across 19 categories, 13 March to 21 April 2026, disclosed crawler, 61,212 references from 7,479 hostnames. Academic, no commercial interest. arxiv.org/abs/2605.14021
2Seer Interactive, AIO Impact on Google CTR: 2026 Update, 24 April 2026. 53 brands, 5,471,127 queries, 2.43bn organic and 296.9m paid impressions, January 2025 to February 2026. Marketing consultancy selling the service the study supports. Limitations disclosed by the publisher are reflected in how the figure is presented above. seerinteractive.com
3Amsive, Google AI Overviews: New Research, April 2025, updated December 2025. 10,000 AI Overview-triggering keywords already ranking organically, from a 700,000-keyword universe across 10 sites. States it lacks significance testing and a control group. Vendor. amsive.com
4Chartbeat data reported by Axios, 17 March 2026. Thousands of publisher sites globally. The 60%, 47% and 22% declines are stated as over the prior two years. Analytics vendor with no stake in this category. axios.com
5Agarwal and Sen, The Impact of Google AI Overviews on Publisher Traffic and User Experience, SSRN, posted 3 April 2026, revised 8 July 2026. Randomized field experiment via browser extension, roughly 1,065 US desktop Chrome users and 68,089 searches, January to February 2026. Working paper, not peer-reviewed. Academic. ssrn.com
6Authoritas, reported by Press Gazette, 30 July 2025. 3,500 UK news-story search terms, of which 426 desktop keywords triggered an AI Overview, over seven days. Submitted to the UK Competition and Markets Authority, so advocacy as well as vendor research. Google disputed the findings. pressgazette.co.uk
7Ahrefs, Google's AI Overviews Now Cost Websites 58% of Their Clicks, 4 February 2026. 300,000 keywords, aggregated Search Console data, desktop only, December 2023 against December 2025. Ahrefs describes it as correlation. Vendor. ahrefs.com
8seoClarity, The Overlap Between AI Overviews and Organic Rankings, published July 2025 and subsequently updated, with the data cited here collected 12 October 2025. 362,000 US desktop keywords, 5.1m citations. The same study reports citation-level top-10 overlap at about 32%, consistent with the 38% Ahrefs figure quoted in Part 3.1. Vendor. seoclarity.net
9Pew Research Center, 22 July 2025. 900 US adults on KnowledgePanel Digital with app-tracked browsing, March 2025, 68,879 searches of which 12,593 produced an AI summary. Independent, non-commercial. pewresearch.org
10Adobe Digital Insights, AI Traffic Trends Report, 19 August 2026. Adobe Analytics across its enterprise customer base plus a survey of 5,000+ US respondents. Adobe sells analytics, not AI-visibility tooling. business.adobe.com
11SurfacedBy, AI citation engine-overlap study, 27 June 2026. 16,400 AI answers, 127,198 citations, 11,647 domains, 29 March to 27 June 2026, commercial-intent questions. States plainly that it measured citations, not clicks. Vendor. surfacedby.com
12Ahrefs, AI Overviews Change Every 2 Days, 11 November 2025. Over 43,000 keywords each with at least 16 recorded AI Overviews, over one month. Authors note checks were not daily, so the real change rate is likely higher. Vendor. ahrefs.com
Also drawn on, not numbered inline
·Google Search Central, Guide to Optimizing for Generative AI Features, updated 10 July 2026. Source of the retrieval and fan-out definitions, the commodity content guidance, the scaled content abuse warning, and the llms.txt, chunking and structured data positions. developers.google.com
·Google Search Console Help: AI features in performance reports, the generative AI report, and the search generative AI control. Source of the counting rules, the impressions-only limitation, and the opt-out behavior. support.google.com
·Ahrefs, schema difference-in-differences study, 11 May 2026, and the llms.txt server-log study, 15 June 2026. Both published by a vendor against its own category interest. ahrefs.com/blog/schema-ai-citations
·Ahrefs, AI Overview citation and ranking overlap, 21 July 2025 and 2 March 2026. Ahrefs states it improved its parsing between the two studies, so the drop from 76% to 38% is partly methodological. ahrefs.com/blog/ai-overview-citations-top-10
·DEJAN, How Big Are Google's Grounding Chunks?, December 2024. 7,060 queries, 883,262 snippets. Measures the Gemini grounding API rather than AI Overviews directly, and is unreplicated. dejan.ai
·Vercel and MERJ, The Rise of the AI Crawler, 17 December 2024. Direct observation of crawler behavior. Vercel sells server-side rendering, so it has an interest in the finding. 21 months old and not replicated. vercel.com
·SALT.agency via Search Engine Land, Core Web Vitals and AI search, 13 January 2026. 107,352 pages, Spearman rank correlation. searchengineland.com
·Contentsquare (99bn sessions, 6,500 sites, April 2026) and SE Ranking (101,574 websites, June 2026) for AI referral share. Semrush for the reasoning-mode instability finding and for AI Overview prevalence through November 2025. Bing Webmaster Blog, 16 June 2026, for the AI Performance report. Ahrefs, 38% of AI Overview Citations Pull From The Top 10, 2 March 2026, 863,000 keyword SERPs and 4 million cited URLs, for the citation-level figure in Part 2.3. Ahrefs freshness study, 28 July 2025, for the 1,432 and 958 day figures. Vercel and MERJ, 17 December 2024, for crawler JavaScript behavior.